Suella Braverman refused to apologise to a Holocaust survivor who said her description of refugees as an "invasion" reminded her of the language used by the Nazis to justify murdering her family.
Ms Braverman was confronted by Joan Salter, 83, during a meeting in her Fareham constituency in Hampshire on Friday evening.
Ms Salter, who has been recognised with an MBE for her work on Holocaust education, likened Ms Braverman's rhetoric on migrants attempting to cross the English Channel to that used by the Nazis during the Second World War.
In footage of the exchange, provided by the charity Freedom From Torture, Ms Salter said: "I am a child survivor of the Holocaust.
"In 1943, I was forced to flee my birthplace in Belgium and went across war-torn Europe and dangerous seas until I finally was able to come to the UK in 1947.
"When I hear you using words against refugees like 'swarms' and an 'invasion', I am reminded of the language used to dehumanise and justify the murder of my family and millions of others.
"Why do you find the need to use that kind of language?"
Ms Braverman thanked Ms Salter for her question, and said that she "shared a huge amount of concern and sympathy" over the "challenge" of illegal immigration, adding that her own parents were not born in Britain.
Speaking about her parents, Ms Braverman said: "They owe everything to this country and they have taught me a deep and profound love of Britain and British people.
"Their tolerance, their generosity, their decency, their fair play.
"That also means that we must not shy away from saying there is a problem.
"There is a huge problem that we have right now when it comes to illegal migration, the scale of which we have not known before.
"I won't apologise for the language that I have used to demonstrate the scale of the problem.
"I see my job as being honest with the British people and honest for the British people.
"I'm not going to shy away from difficult truths nor am I going to conceal what is the reality that we are all watching."
Ms Braverman added that she was "incredibly proud" of the UK's recent immigration record but added that "we have a problem with people exploiting our generosity, breaking our laws and undermining our system".
"We must accept the enormity of the problem if we've got any chance of solving it," she said.
Ms Braverman's answer was greeted with applause from the audience.
Born Fanny Zimetbaum in Brussels in 1940 to Polish Jewish parents, Ms Salter was three months old when Belgium was invaded by the Nazis.
Following the invasion, she escaped to France with her mother and sister before being taken by the Red Cross to the US in 1943.
Ms Salter remained in foster care in America until being reunited with her parents in 1947 in London, where she has lived since.
Less than a week into her tenure as Home Secretary under Prime Minister Rishi Sunak, Ms Braverman referred to her job as being "about stopping the invasion on our southern coast".
She had previously held the post under Liz Truss from September 6 until October 19, when she resigned for breaching the ministerial code by sharing an official document from her personal email address.
Ms Braverman has not used the word "swarm" on record, but it has been used by prominent politicians including former Prime Minister David Cameron and former UK Independence Party (Ukip) leader Nigel Farage.
In July 2015 Mr Cameron told journalists that "a swarm of people" were "coming across the Mediterranean seeking a better life".
In the same month, Mr Farage said during an ITV interview that he had been "stuck on the motorway and surrounded by swarms of potential migrants" who "tried the back door of the car to see whether they could get in".
He later back-pedalled, telling an interview with BBC Radio 4's Today programme that he did not "use language like that" when asked if he would refer to migrant "swarms".
